While the T-Mobile and Orange brand will co-exist alongside the new brand, EE will primarily be focused on providing fiber optic broadband and 4G LTE service. EE's new 4G network will be based on LTE (using band 800Mhz and 2600Mhz if I remember correctly). Four initial cities - London, Birmingham, Cardiff and Bristol, are currently on trial.
Phones already confirmed to be launching on the network includes the Samsung Galaxy S III LTE, HTC One XL, Huawei Ascend P1 LTE, Nokia Lumia 820 and Nokia Lumia 920, which will be an EE exclusive.. Also heavily hinted upon is the next generation Apple iPhone (5), rumoured to include LTE connectivity, due to be announced tomorrow.
In the meantime, check out the hands-on video of the Samsung Galaxy S3 LTE and Huawei Ascent P1 LTE version for a taster of what LTE can bring.
Samsung Galaxy S III LTE
Huawei Ascent P1 LTE